Whenever possible, surgeons prefer to perform surgery endoscopically. To perform endoscopic surgery, an endoscope is inserted into the body at the surgical site. The endoscope is an elongated tube that allows a surgeon to view the portion of the body into which it is inserted. Other surgical instruments inserted in the body at the surgical site can be manipulated based on what the surgeon views through the endoscope. The development of endoscopes, as well as their companion instruments, has made it possible to perform minimally invasive surgery. In this type of surgery, the need to make large incisions to gain access to the surgical site has been eliminated. Instead, the surgeon can insert an endoscope and other equipment through small openings in the body, called portals. One advantage to endoscopic surgery is that since the incisions are smaller, the portions of the body that need to heal after surgery are reduced. Additionally, because less of the internal tissue of the patient is open to the environment, the extent to which the patient's tissues and organs are open to infection is reduced.
Initially, endoscopes included only an eyepiece, through which the surgeon could view the surgical site. A modern endoscope system includes a camera assembly that has a camera head attached to the proximal end of the endoscope. A signal processor receives output signals from the camera head. The output signals are converted by the signal processor into electronic signals that are displayed on a monitor. By providing this type of system, the surgeon and other personnel in the operating room can readily view the surgical site by observing the monitor.
Typically, a lens assembly is included in the endoscopic system between the proximal end of the endoscope and the camera head. The lens assembly is fitted in a coupler attached to the proximal end of the endoscope. The lens assembly includes one or more lenses that are moved to focus the image on a transducer internal to the camera head. The lens assembly may also include one or more lenses that are moved to selectively magnify the image.
The camera assemblies of modern endoscope assemblies are also capable of processing the output signals generated by their camera heads in order to display the images desired by a surgeon. Specifically, these assemblies are capable of magnifying a portion of the received output signals in order to produce an enlarged image of a section of the surgical site. One such system is disclosed in U.S. Pat. No. 6,224,542, entitled, Endoscopic Camera System With Non-Mechanical Zoom, issued on May 1, 2001, which is incorporated herein by reference.
These assemblies are also capable of enhancing the received camera head output signals in order to facilitate the generation of an image in which the features of the captured images are clearly presented on the camera display. One such system for enhancing the captured image is disclosed in the Applicants' Assignee's U.S. Pat. No. 6,533,721, issued Mar. 18, 2003, entitled ENDOSCOPIC CAMERA SYSTEM WITH AUTOMATIC NON-MECHANICAL FOCUS, filed Jul. 27, 2001 and incorporated herein by reference.
During a surgical procedure, the surgeon may want to periodically modify the magnification, the field of view, of the surgical site that is displayed on the monitor. In order to accomplish this task, it is often necessary for the surgeon or the operating room personnel to alternatively adjust the position of the lenses internal to the coupler and the magnification setting of the video signal processor. The time and concentration required to make these adjustments, both lengthens time needed to perform the surgical procedure and diverts attention from the surgical procedure.
Also, sometimes during the course of a surgical procedure, the quality of the image of the surgical site presented by the endoscope system may deteriorate. This may necessitate having to readjust the position of the lenses internal to the coupler and/or the video image processing performed by the camera position. Again, having the surgeon or other surgical personnel perform these tasks can divert attention away from the actual surgical procedure the surgeon is attempting to perform and can lengthen the overall time it takes for the procedure to be performed. This runs contrary to one of the goals of modern surgery which is to perform the surgical procedure as quickly as possible in order to minimize the amount of time a patient must spend under anesthetic.